MPI Project Review BepiColombo-a planetary mission to Mercury Focal plane instrumentation for the MIXS instrument Ringberg, 24.4.2007 Mercury as seen on 16.9.2004 1 Johannes Treis MPI Halbleiterlabor
Institutions 2 Johannes Treis MPI Halbleiterlabor
Contents � History of Mercury observation � The Planet Mercury � BepiColombo � The MIXS Instrument � The FPA detector for MIXS 3 Johannes Treis MPI Halbleiterlabor
History of mercury observation ~ 3000 B.C: First known evidence of Mercury observations by sumerian priests in mesopotamia. Planet known as Ubu-idim-gud-ud Ziggurat of Ur ~ 1000 B.C: Detailed recordings of Mercury observations by babylonian astronomers Planet known as Nabu or Nebu , referring to the babylonian messenger of gods, due to its swift movement and partial Babylonian record visibility. of Venus observation 4 Johannes Treis MPI Halbleiterlabor
History of Mercury observation ~ 500 B.C: Greek astronomers give Mercury two names, Stilbon and Hermaon , depending whether it is visible in the morning or evening. Pythagoras of Samos proposes that the two observations refer to a common body, which is then called Hermes, after the greek messenger of gods, which is later identified with the roman god Mercury. In roman/greek mythology, Mercury is not only the messenger of gods and the god of travellers, but also the god of merchants, of crooks, liars and highwaymen. Statue of Mercury by Giambologna (16th century, Florence) 5 Johannes Treis MPI Halbleiterlabor
History of Mercury observation Always displayed with the winged herlad’s staff wound by two snakes (caducaeus), winged sandals (talaria) and winged traveller’s hat (petasos), which inspired the astronomical symbol for Mercury: Rarely displayed alone, but either participating on assemblies of gods (mostly just arriving or leaving) or while delivering a message to a recipient. Is also said to explain the somewhat obscure messages of the gods to the mortals. Engl.: French: Merchant Merci Commerce Mercredi Mercury (Hg) Mercenary Mercury in the staircase fresco by Gianbattista Tiepolo at the Wuerzburg residence (18 th century). Wednesday 6 Johannes Treis MPI Halbleiterlabor
History of mercury observation ~ 1610: First telescopic observations of Mercury by Galileo Galilei 1631: The Mercury transit predicted by Johannes Kepler is observed by Pierre Gassendi, which is the first known observation of a planetary transit. 1639: Giovanni Zulpi discovers Mercury’s phases by telescopic observation, Transit of Mercury, 7.5.2003 which proves that mercury orbits around the sun. 1737: John Bevis records the first his- torically observed Mercury occul- tation by Venus (28.5.1737) Next: 2133. 1800: First observation of surface features by Johann Schroeter. 1881: First surface map of mercury by Giovanni Schiaparelli. 7 Johannes Treis MPI Halbleiterlabor
History of Mercury observation ~ 1930: Mercury’s orbit irregularities are explained by GRT! ~ 1960: Discovery of anomalous tidal locking of orbital period to rotational period by radio observations 1965: Precise measurement of the planet’s orbital period. Guiseppe (Bepi) Colombo suggests an anomalous resonant tidal locking with a 3:2 ratio, i.e. Mercury rotates three times for every two revolutions round the sun. 1974: Until 1975, Mariner 10 passes Mer- cury 3 times. Flight plan suggested by Bepi Colombo included Venus- Swing-Bys. Unexpectedly, the revolu- tion period of Mariner 10 in this or- bit was exactly twice the revolution period of Mercury, so that only ~45 % of mercury could be cartographed. Mariner 10 2000: Lucky imaging observations at Mount Wilson reveal details of the uncartographed region. Observation with x-ray satellites. 8 Johannes Treis MPI Halbleiterlabor
Future of Mercury observation 2004: Launch of the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) probe by NASA. January 2008: First Mercury flyby October 2008: Second Mercury flyby September 2009: Third Mercury flyby March 2011: Entering Mercury orbit 1 year of mission lifetime Payload similar to BC, but simpler Pathfinder for BC 9 Johannes Treis MPI Halbleiterlabor
Future of Mercury observation 2013: Launch of ESA’s mission BepiColombo 10 Johannes Treis MPI Halbleiterlabor
The planet Mercury Earth Venus Mercury Sun (to scale) Radii to scale 11 Johannes Treis MPI Halbleiterlabor
Mercury fact sheet 0.46 – 0.3 AU (70 – 46 x10 6 km) Orbital radius: Radius: ~2440 km (34% of earth) 3.302×10 23 kg Mass: Least well-known of Density: 5.43 g / cm 3 the terrestrial planets Surface gravity: 3.7 m / s 2 Rotation period: ~58 d Orbital period: ~85 d Axial tilt: 0.01° Incination: ~ 7 ° Albedo: 0.1 Atmosphere: Traces (H, He, O, K, Na, Ca) Surface temperatures: � Very small magnetic field Equator North pole (1% of earth) Mean: 70 °C -70 °C � No moons Min: -170 °C -190 °C � Ice? Sulphur? Max: 430 °C 107 °C 12 Johannes Treis MPI Halbleiterlabor
Mercury surface � Moon-like surface, heavily cratered � Basins (volcanism) � Geologically inactive for a long time � Weird morphologhic features Rupes Weird terrain Caloris basin 13 Johannes Treis MPI Halbleiterlabor
Mercury mass Anomal density! Inhomogeneous mass distribution (spin-orbit • Terrestrial planet bulk composition resonance)! derives from equilibrium condensation from the solar nebula. • Not for Mercury – unpredicted large uncompressed density • Large core – thin mantle – high Fe content, observations imply low Fe. • Possibilities 1. Selective accretion 2. Post Accretion Vaporisation 3. Massive Impact 14 Johannes Treis MPI Halbleiterlabor
Mission targets Giuseppe “Bepi“ Colombo (2.10.1920 – 20.2.1984) ESA cornerstone mission: � Origin and evolution of a planet close to the parent star � Mercury as a planet: form, interior, structure, geology, composition and craters � Detect traces of Mercury's vestigial atmosphere (exosphere): composition and dynamics � Mercury's magnetized envelope (magnetosphere): structure and dynamics � Origin of Mercury's magnetic field � Test of Einstein's theory of general relativity Mercury surface as seem by Mariner 10 ...collaboration with JAXA 15 Johannes Treis MPI Halbleiterlabor
BepiColombo � Launch 2013 � Platform: Soyuz Fregat B � MCS: Mercury composite spacecraft � 6 year long journey � Main challenges: • Thermal management Mercury composite spacecraft (MCS) • Power (!) • Radiation damage • Flight plan 16 Johannes Treis MPI Halbleiterlabor
BepiColombo MCS exploded view Mercury magnetospheric orbiter (MMO) Mercury planetary orbiter (MPO) Solar shield Mercury transfer module (MTM) 17 Johannes Treis MPI Halbleiterlabor
BepiColombo � Scheduled arrival: 2019 � On arrival: Deployment of MPO and MMO in their respective orbits � 1 year of expected mission lifetime � Possible prolongation by another year 18 Johannes Treis MPI Halbleiterlabor
Mercury magnetospheric orbiter Instruments: � MERMAG-M: Magnetometer � MPPE: Mercury plasma particle experiment � PWI: Plasma wave experiment � MSASI: Mercury Sodium Atmospheric Spectral Imager � MDM: Mercury dust monitor zum Selberbasteln... 19 Johannes Treis MPI Halbleiterlabor
Mercury planetary orbiter Instruments: � BELA: Laser altimeter � ISA Accelerometer � MERMAG: Magnetometer � MERTIS: Thermal infrared spectrometer � MGNS: Gamma-ray and neutron spectrometer � MIXS: x-ray spectrometer � MORE: Radio science Ka-Band transponder � PHEBUS: UV-Spectrometer � SERENA: Neutral and Ionized particle analyzer � SIMBIO: High resolution and stereo camera, visible and NIR spectrometer � SIXS: Solar monitor 20 Johannes Treis MPI Halbleiterlabor
The MIXS Instrument • Incident solar X-rays induce X-ray fluorescence from the surface • Potentially an additional component induced by incident protons and electrons • Precise intensity monitor needed! 21 Johannes Treis MPI Halbleiterlabor
The MIXS Instrument � MIXS : M ercury I maging X -ray S pectrometer � Measure fluorescent X-rays from Mercury surface � First few micron of depth are explored � Solar Intensity X-ray Spectrometer (SIXS) provides reference information � Detection of characteristic lines allows to determine element abundance � Combination with IR measurements (MERTIS) yields mineralogy information � Combination with soft γ -ray measurements (MGNS) yields element abundance in depth of ~1 m � Average composition of Mercury’s � Correlation of surface Na, K and Ca crust with complementary measurements of � Compositions of the major terrains exosphere � Composition inside craters and � probe of the surface-magnetosphere- crater structures exosphere system � Detection of iron globally and � Sulphur at the poles and in the crust locally globally � Chromium to Nickel ratio globally to constrain formation models 22 Johannes Treis MPI Halbleiterlabor
MIXS � Two cameras � Telescope: MPC optics � Same focal plane detector � MIXS-C: Wide field imaging � Different optics � MIXS-T: Precise Mapping � Collimator (MIXS-C) and Footprint size: Telescope (MIXS-T) � 14 km for periherm � 52 km for apoherm MIXS-T FPA MIXS-C FPA 23 Johannes Treis MPI Halbleiterlabor
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